''Hemolivia'' (also spelled ''Haemolivia'') is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Apicomplexia The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic Alveolata, alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex stru ...

History

This genus was described in 1990 by Petit ''et al''. The type species is '' Hemolivia stellata''. Molecular data on ''H. stellata'' were provided in 2015 by Karadjian, Chavatte and Landau, from a 25-year-old archived smear of crushed tick ('' Amblyomma rotondatum''). ''Hepatozoon argantis'' Garnham, 1954 was reassigned to ''Hemolivia'' as ''

Hemolivia argantis ''Hemolivia'' (also spelled ''Haemolivia'') is a genus of the phylum Apicomplexia. History This genus was described in 1990 by Petit ''et al''. The type species is '' Hemolivia stellata''. Molecular data on ''H. stellata'' were provided in 20 ...

'' (Garnham, 1954) Karadjian, Chavatte and Landau, 2015.

Characteristics of the genus

The species in this genus are

haemogregarine ''Adeleorina'' is a suborder of parasites in the phylum Apicomplexa. History Léger proposed this taxon in 1911. The first species identified was '' Dactylosoma ranarum'' by Lankester (1871) in a frog in Europe. It was initially called ''Unduli ...

s and infect exothermic vertebrates. They have erythrocytic

gamogony Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

, both erythrocytic and extra-erythrocytic merogony and cystogony. The definitive hosts are

ixodid tick The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'sof ...

s. Sporogony occurs in two phases. In the first phase

conjugation Conjugation or conjugate may refer to: Linguistics * Grammatical conjugation, the modification of a verb from its basic form * Emotive conjugation or Russell's conjugation, the use of loaded language Mathematics * Complex conjugation, the chang ...

and

fertilization Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

occur within the tick gut. This is followed by the formation of

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

s and the generation of sporokinetes. In the second phase the sporokinetes invade the body of the tick and give rise to sporocysts containing sporozoites infective to the vertebrate host.

Life cycle

The

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

of this species is the cane toad (''

Bufo marinus The cane toad (''Rhinella marina''), also known as the giant neotropical toad or marine toad, is a large, terrestrial true toad native to South and mainland Central America, but which has been introduced to various islands throughout Oceania ...

''). The

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

host is the tick '' Amblyomma rotondatum''. Toads become infected by ingesting infected ticks. The sporozoites are released from the sporocysts within the tick and penetrate the intestinal wall. Within the toad they replicate within the

endothelial cell The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...

s and

erythrocyte Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s. Liver cysts may form. Circulating gamonts are then ingested by a tick. Within the tick gut the gamonts form pairs and penetrate the epithelial cells. Within these cells they associate in syzygy. Gametes are formed and fuse forming an

. The oocysts are star shaped. The oocyst undergoes meiosis and then mitosis producing numerous sporozoites. These sporozoites invade the body of the tick, undergo merogony and giving rise to many

merozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

s which are infective for the toad.

Host records

''H. mariae'' - blue-tongued skink ('' Tiliqua rugosa'') ''H. mauritanica'' - Greek tortoise (''

Testudo graeca The Greek tortoise (''Testudo graeca''), also known commonly as the spur-thighed tortoise, is a species of tortoise in the family Testudinidae. ''Testudo graeca'' is one of five species of Mediterranean tortoises (genera '' Testudo'' and '' Ag ...

''), marginated tortoise (''

Testudo marginata The marginated tortoise (''Testudo marginata'') is a species of tortoise in the family Testudinidae. The species is endemic to Greece, Italy, and the Balkans in Southern Europe. It is the largest European tortoise. The marginated tortoise is he ...

''), '' Testudo mauritanica'' ''H. stellata'' - teiid lizard (''

Ameiva ameiva ''Ameiva ameiva'', also known as the giant ameiva, green ameiva, South American ground lizard, or Amazon racerunner, is a species of lizard in the family Teiidae found in Central, South America, and some Caribbean Islands. Geographic range It ...

''), cane toad (''

'')

Vectors

''H. mariae'' - '' Amblyomma limbatum'' ''H. mauritanica'' - ''

Hyalomma aegyptium ''Hyalomma'' is a genus of hard-bodied ticks common in Asia, Europe, and North Africa. They are also found in Southern Africa. The name is derived from Greek: hyalos (ὕαλος) crystal, glass; and omma (oμμα) eye. The genus is believed to ...

'' ''H. stellata'' - '' Amblyomma rotondatum''.

References

{{Taxonbar, from=Q5712497 Apicomplexa genera